We are seeking financial support for PIs, post-doctoral fellows and graduate students working in US laboratories planning to participate in the 9th Meeting of the International Motoneuron Society scheduled for June 2014. The goal of these highly successful, international meetings is to bring investigators working on motoneurons and motor units in animal models together with those performing analogous studies on human subjects. A major emphasis of the discussions is on translating basic science advances into clinical therapies. This field is unusually international, with the key laboratories scattered throughout North America, Europe and Australia. Thus, these meetings have been essential for maintaining communication and progress in the field, and they have fostered a number of important collaborative projects. NINDS has generously supported several of the prior meetings in this series (Boulder, 2000; Boulder, 2004; Seattle, 2008, Paris, 2010 and Sydney, 2012). To facilitate interactions between the participating labs at the meeting, each session consists of an introduction for non-specialists, short presentations, and extended time for discussion. Each session will have at least one presentation by a post-doctoral fellow or a graduate student. Sessions on cellular physiology from animal models are interspersed with related studies on human subjects throughout the meeting. We also include discussions of recent developments in high speed, biologically realistic computer simulations that potentially provide a platform for quantitatively relating these two types of data. The issue at the heart of the meeting is how can the experimental results and computer simulations be best integrated to resolve the cellular mechanisms underlying motor unit firing patterns both in normal function (fatigue, exercise) and in disease states (spinal injury, hemiparetic stroke, ALS and SMA). A new addition at this meeting will be the inclusion of clinician-scientists who will address therapeutic approaches to motor pathologies. The abstracts submitted by each invited speaker will be posted on a publicized website. Following the meeting, video recordings of the talks and discussion sessions will be uploaded to the expanded website. We anticipate that this will generate new ideas and approaches for investigation of motor systems as well as creation of new therapeutic strategies for spasticity in spinal injury and stroke and motoneuron degeneration in ALS and SMA.